Description:
------------
#0  0x083afc55 in zend_std_object_get_class (object=0x9f5ca88, tsrm_ls=0xb772b600) at /home/php-5.4.8/Zend/zend_object_handlers.c:1450
1450	{
(gdb) bt
#0  0x083afc55 in zend_std_object_get_class (object=0x9f5ca88, tsrm_ls=0xb772b600) at /home/php-5.4.8/Zend/zend_object_handlers.c:1450
#1  0x082f90c1 in php_var_serialize (buf=0x9fc3150, struc=0xb6d30f3c, var_hash=0xb6d30f38, tsrm_ls=0x9f5ca88) at /home/php-5.4.8/ext/standard/var.c:899
#2  0xb6d3a03e in pthreads_store_tostring (unstore=0x2, tsrm_ls=<value optimized out>) at /home/pthreads-0.0.38/src/store.c:182
#3  pthreads_store_create (unstore=0x2, tsrm_ls=<value optimized out>) at /home/pthreads-0.0.38/src/store.c:273
#4  0xb6d3a60a in pthreads_store_separate (pzval=0x0, separated=0xb650e354, allocate=1 '\001', tsrm_ls=0x9f5ca88) at /home/pthreads-0.0.38/src/store.c:143
#5  0xb6d391e1 in pthreads_prepared_entry (thread=0x9f5c348, candidate=0xb6f05c5c, tsrm_ls=0x9f5ca88) at /home/pthreads-0.0.38/src/prepare.c:213
#6  0xb6d395e0 in pthreads_prepare (thread=0x9f5c348, tsrm_ls=0x9f5ca88) at /home/pthreads-0.0.38/src/prepare.c:311
#7  0xb6d3cc6b in pthreads_routine (arg=0x9f5c348) at /home/pthreads-0.0.38/src/object.c:619
#8  0xb7097955 in start_thread () from /lib/i686/cmov/libpthread.so.0
#9  0xb70171de in clone () from /lib/i686/cmov/libc.so.6


Test script:
---------------
<?php
dl('pthreads.so');
error_reporting(E_ALL);
class ThreadTest extends Worker {

	public $t = 0;
	public function run(){
		$i=0;
		while(true){
			if ($this->t == 1) { echo "counter++\n"; test::instance()->counter++; }
			if ($this->t == 2) {
				try {
				echo "test123\n";
				echo test::instance()->getCounter()."\n";
				echo "test123\n";
			} catch (Exception $ex) {
				echo $ex->getMessage();
			}
			}
			sleep(rand(1, 3));
		}
		return $i;
	}
}

class test {
	
	static private $ins = null;
	
	public static function instance() {
		if (self::$ins == null) {
			self::$ins = new test();
		}
		
		return self::$ins;
	}
	
	public $counter = 1;
	
	public function getCounter() {
		return "c:".$this->counter;
	}
	
}

$counter = 1;

echo "test: ".test::instance()->getCounter()."\n";


$thread = new ThreadTest();
$thread->t = 1;
$thread2 = new ThreadTest();
$thread2->t = 2;
if($thread->start() && $thread2->start()) {
	sleep(60);
}